My 10 year old asked me my opinion about whether we should keep the English System, or go to the metric system, and I realized I didn't really have an opinion about this. Upon reflection, I decided that I think the English system is the way to go, for these reasons.
Let's suppose that when measuring temperature, the normal range of air temperature in Degrees Fahrenheit at normal human occupied geographies is between 0 and 100. Just go with me. In Celsius that would be -18 to 37 degrees. There are roughly 55 degrees celsius in that range, a little over half the increments in fahrenheit. So, the normal range of temparature that humans deal with on a day to day basis is better mapped with more increments and more positive regular numbers by Fahrenheit.
This is true across the board. What is the metric equivalent of a gallon? There isn't one! Who honestly ever talks about decaliters or centilters or whatever? The arbitrary division of basic units by 10 doesn't map well to human experience. The units in the English system arose organically over time to measure things that human beings actually do. It is a bit of a mess, but it makes sense to us because there are units for things that we actually need units for. If you go into Canada, they measure distance in Km, but land is still sold by the acre. Why? It makes more sense to measure land that way than by the square meter or square Km.
The metric system was created by some scientists in the absence of thinking about how well it mapped to most of human experience. It is a wonderful experiment but I think the resistance to it is more than simple inertia; there is a reason that in some places like the US it is very much persisting.